Spray shield for oil wells

ABSTRACT

A spray shield assembly for oil wells which require artificial lift apparatus The shield assembly includes a hollow bonnet member and a seal assembly wherein the seal assembly is supported in overlying relationship relative to a stuffing box on an oil well. The bonnet member is affixed to oil well structure by resilient biasing means. A polished rod is sealingly and reciprocatingly received axially of the bonnet member and the seal assembly. The spray shield is made in component parts which are joined together in a manner which enables its assembly to the well head without the necessity of dismantling any portion of the pumpjack.

United States Patent [191 Edge et al. Jan. 8, 1974 SPRAY SHIELD FOR OIL WELLS Primary Examiner-Marvin A. Champion [76] Inventors: Billy J, Edge; Lloyd 0. Collins, both Assmm hammer-Lawrence Saab of PO. Box 6487, Odessa, Tex. Bates 79760 [22] Filed: Mar. 30, 1972 [57] ABSTRACT PP 239,699 A spray shield assembly for oil wells which require artificial lift apparatus The shield assembly includes a 52 Us. (:1. 166/81, 166/84 hollow bonnet member and a Seal assembly wherein 51 Int. (:1 E2116 33/03 the seal assembly is Supported in veflying 58 Field of Search 166/81, 84 Ship relative to Swffing box on well- The bonnet member is affixed to oil well structure by resil- 56] References Cited ient biasing means. A polished rod is sealingly and re- UNITED STATES PATENTS ciprocatingly received axially of the bonnet member and the seal assembly. 3,322,198 5/1967 McHenry l66/8l 1,632,389 6/1927 Davis The spray shleld 15 made 1n component parts WlllCh 2,213,923 9/1940 Stuart et 31mm are joined together in a manner which enables its 2,318,466 5/1943 Cooper assembly to the well head without the necessity of 2,634,812 4/1953 Allemang dismantling any portion of the pumpjack. 3,270,810 9/1966 Johnston 166/81 5 Claims, 8 Drawing Figures PATENTED JAN 8W4 FIG. 7 b I42 SPRAY SHIELD FOR OIL WELLS BACKGROUND OF THE INVENTION Many oil wells are located within cities and towns and often adjacent to valuable crop lands. Where the oil well is provided with a pumpjack for lifting oil from the borehole, a polished rod reciprocatingly extends through a stuffing box which forms a seal means between the rod and the well head. Underlying the well head there is usually a cavity or graveled area, called a cellar, which forms the upper terminal end of the borehole. Normal drainage of liquids flowing or leaking from the well head is-received within the cellar so as to prevent petroleum .products or well fluid from being washed into the Watershed.

Economically it is impossible to continuously monitor the pumpjack and well head. Accordingly, from time to time, the packing in the stuffing box will fail, thereby allowing the well fluids produced by the downhole pump assembly to spray into the atmosphere, whereupon the immediate vicinity is contaminated by smelly, dirty well fluids '-which include hydrocarbons, wax, salt water, hydrogen sulphide, and various other petroleum products. Such a catastrophe must be reconciled by the owner of the oil well, and usually involves the expensive undertaking of cleaning and repainting homes, purchase of growing crops, and replanting of trees.

It is desirable to provide means for use in conjunction with a stuffing box on a well head that precludes the spraying of well fluid into the atmosphere upon failure of the stuffing box packing. One prior art apparatus for accomplishing this purpose is disclosed in U.S. Pat. No. 3,270,810 to Johnson.

In the prior art shields for stuffing boxes it has been generally necessary to remove the polished rod from the cross-beam of the pumpjack so as to enable various components thereof to be placed thereabout. Moreover, some prior art protectors of this type will be dislocated or misaligned relative to the well head upon being struck by the force of the well fluid as it sprays through the ruptured packing gland of the stuffing box.

The present invention overcomes the above objections and provides for the above desirable expedients by the provision of improvements in a spray shield, as set forth in the following specification.

SUMMARY OF THE INVENTION The present invention comprehends a spray shield assembly having a downwardly opening hollow bonnet member which depends from and is supported by a seal assembly. The seal assembly telescopingly receives a polished rod of a pumpjack therethrough with a lowermost member of the assembly being supported on an uppermost portion of a stuffing box.

Biasing means maintains the spray shield properly secured and aligned relative to the well head, the stuffing box, and the polished rod so that impingement of a spray. of well fluid against the shield will not damage nor permanently dislodge the shield from its operative position relative to the well head.

Accordingly, a primary object of this invention is the provision of a spray shield which prevents well fluids from contaminating the atmosphere or surrounding areas of an oil well.

Another object of the invention is to provide a spray shield for a well head which maintains the polished rod in a clean and operative condition and prevents contamination of the immediate surroundings.

A further object of this invention is to disclose and provide a spray shield which is resiliently affixed to a well head in a manner whereby damage from well fluids under pressure is obviated.

A still further object of this invention is to provide a spray shield assembly for use in conjunction with the pumping system of an oil well which can be assembled without the necessity of disassembling any part of the wellhead.

These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims, and by referring to the accompanying drawings.

The above objects are attained in accordance with the present invention by the provision of a combination of elements which are fabricated in a manner substantially as described in the above abstract and summary.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary side elevational view with some parts thereof being broken away and which shows apparatus made in accordance with the present invention operatively positioned on a well head;

FIG. 2 is an enlarged top plan view of the invention disclosed in FIG. 1;

FIG. 3 is a part cross-sectional view taken along line 33 of FIG. 2;

FIG. 4 is a fragmentary side elevational view which discloses an important feature of the present invention;

FIG. 5 is an enlarged fragmentary part crosssectional representation of part of the apparatus seen in the foregoing figures;

FIG. 6 is an exploded view of part of the apparatus seen in FIG. 5; and

FIGS. 7a and 7b are enlarged fragmentary crosssectional detailed representations of a modification of a teaching set forth in FIGS. 2 and 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Numeral 10 in FIG. 1 generally indicates a well head having a production tubing 1 1 which extends into a cellar 12. The cellar forms the upper terminal end of a borehole. Outflow lines 13 are flow connected to the production tubing and can take on several different forms and configurations. A stuffing box 14 has an upper terminal end portion 114 and sealingly receives a polished rod 15 in a reciprocating manner therethrough, with the polish rod extending downhole where it is connected to-numerous series connected sucker rods which in turn acutate a downhole pump.

A spray shield assembly, generally indicated by the arrow at numeral 16 is comprised of a seal assembly 17 from which there downwardly depends a hollow bonnet member. The member includes an inverted frustro cone 18 having the minor diameter thereof connected to the seal assembly and the major diameter thereof connected to the upper peripheral edge portion of a downward disposed skirt member 19.

Diametrically opposed springs 20, 21 have one end thereof affixed to the apertured lower marginal edge portion of the skirt while the remaining end thereof is affixed to the illustrated cable 22 while the cable is rove about portions of the well head in any convenient manner so as to firmly but resiliently maintain the spray shield affixed to the Christmas tree.

As seen in FIGS. l and 3, the biasing means or springs are each attached to the skirt member by means of a hook 23 which provides for rapid disengagement of the shield from the well head. Enlargement 24 forms a lower terminal end of the skirt member, with apertures 25 receiving the before mentioned hook therethrough. The enlargement provides ample bearing and wearing surface for accommodation of the spring force.

Spaced apart upper and lower wall members 26, 27 define a hollow body member in the form of an annulus within which the various illustrated gaskets and seals are disposed. Annular groove 28 is formed intermediate spaced apart walls 26 and 27 of the seal housing. The spaced apart walls include an inner wall surface which forms an axial passageway at 29, 30 and which telescopingly receives the polished rod in a reciprocating manner therethrough. An annular flange 30 presents a shoulder 31 which bears against the uppermost surface 114 of the stuffing box, and forms the support means for the shield assembly.

As seen in FIG. 5, together with FIG. 6, a split felt washer or gasket 32 is in the form of a discontinuous toroid and has an i.d. slightly smaller than passageway 29 so that the washer slidably bears against the polish rod in low friction engagement therewith. Teflon bearing member 33 is provided with an i.d. 34 which engages the outer peripheral surface of the polished rod in close tolerance relationship therewith. Outwardly directed flange 35 of the bearing is received within the before mentioned groove 28 so that the bearing is captured within the seal housing. Upper and lower edge portions 36, 36' of the bearing bear against the felt washers so that the washers are compressed within the housing.

Diametrically opposed vertical bolt flanges 38, 39 enable the spray shield to be made from identical semicircular members 116, 216 thereby greatly reducing the cost thereof. The flanges are apertured and fastened together by means of spaced apart fasteners such as a bolt 40, for example.

As disclosed in the embodiment of FIG. 7a, a tongue 41 and groove 42 can be substituted for the vertical bolt flange so as to enable members 116' and 216' to be joined together by fastener means 43. I

As illustrated in FIG. 7b, the tongue and groove fastener means M1, 142 enables the two semicircular members 116 and 216" to be releasably fastened together with a snap action. Accordingly, male member 142 is forced into cavity 141 to form an inexpensive fastener means which can be disassembled rapidly.

In operation, the two halves 116, 216 of the spray shield are fitted with the seal member placed as disclosed in FIG. 5, and the two halves mated together with the polished rod being received through the axial passageway formed by the seal assembly. The annular flange 31 is then firmly seated upon the stuffing box. Springs 20, 21 are placed within the diametrically opposed apertures 25 after the cable has been suitably rove about portions of the well head so as to place the springs in tension, thereby resiliently biasing the skirt member in a downward direction with the flange 31 being brought to bear against the stuffing box.

The polished rod is maintained free of debris as it reciprocates within the seal assembly, thereby prolonging the life of the packing associated with the stuffing box.

In the event the packing of the stuffing box should malfunction; whereupon well fluid flows from between the polished rod and the upper extremity of the stuffing box, the well fluid will be contained within the hollow bonnet member as it is directed in a downward direction so that the well fluid flows into the cellar rather than contaminating the atmosphere in close proximity of the well. i

It will be evident from the structure illustrated in FIGS. l and 5 that the biasing means connected to the spray shield are preferably in the form of metal springs having one of the opposed end portions thereof placed in engagement with the lower marginal edge portion of the skirt member and the remaining end portion thereof arranged for engagement with the well head so that the biasing means releasably holds the spray shield positioned about the stuffing box. Accordingly, as the well fluid sprays into the bonnet the springs will permit the spray shield to separate a limited distance from the stuffing box in the illustrated manner ofFIG. 5, if the force is violent. The presence of the seal assembly precludes the flow of well fluid through the upper portion of the assembly, and accordingly, the spray is contained within the immediate area by the shield.

I claim:

1. In combination with a stuffing box having a polished rod reciprocatingly receivedtherewithin, a spray shield assembly havmg a downwardly opening hollow bonnet member and a seal assembly, said seal assembly including a hollow body member having a lower end portion in the form of an annular flange which is adapted to be supportingly received upon an uppermost portion of the stuffingbox with the polished rod being axially aligned with and extending through said annular flange;

said hollow bonnet memberv having a circumferentially extending wall in the form of an inverted frusto cone and a vertically disposed cylindrical skirt member, with the minor diameter of said cone being affixed to said seal assembly, and with the major diameter of said cone being affixed to an upper edge portion of said skirt member so as to leave a free depending loweredge portion of the skirt member in underlying relationship respective of the stuffing box;

biasing means connected to said spray shield, said biasing means include spaced spring means, each said spring means having opposed end portions with one end portion being placed in engagement with the lower marginal edge portion of said skirt member and the remaining end portion of each said spring means being arranged for engagement with a well head so that said biasing means releasably holds the spray shield positioned about the stuffing box.

2. The apparatus of claim ll wherein said spray shield is made of two separate assemblies joined together along an interface defined by a vertical plane which passes through the central axis thereof;

and fastener means for releasably holding together said joined together assemblies.

3. The apparatus of claim 2 wherein said hollow body member of seal assembly includes an upper annular flange spaced apart from the before mentioned flange to thereby form an annulus seal housing therebetween;

said seal assembly further including spaced apart gasket members located within said housing for seal- 5. The combination of claim I wherein said sea] assembly includes a split annular gasket in the form of a discontinuous toroid having an inside diameter for sealingly receiving a polished rod therethrough, and having an outer diameter for being received within said hollow body member in close tolerance relationship therewith, so that said seal assembly protects the polished rod stuffing box from debris. 

1. In combination with a stuffing box having a polished rod reciprocatingly received therewithin, a spray shield assembly having a downwardly opening hollow bonnet member and a seal assembly, said seal assembly including a hollow body member having a lower end portion in the form of an annular flange which is adapted to be supportingly received upon an uppermost portion of the stuffing box with the polished rod being axially aligned with and extending through said annular flange; said hollow bonnet member having a circumferentially extending wall in the form of an inverted frusto cone and a vertically disposed cylindrical skirt member, with the minor diameter of said cone being affixed to said seal assembly, and with the major diameter of said cone being affixed to an upper edge portion of said skirt member so as to leave a free depending lower edge portion of the skirt member in underlying relationship respective of the stuffing box; biasing means connected to said spray shield, said biasing means include spaced spring means, each said spring means having opposed end portions with one end portion being placed in engagement with the lower marginal edge portion of said skirt member and the remaining end portion of each said spring means being arranged for engagement with a well head so that said biasing means releasably holds the spray shield positioned about the stuffing box.
 2. The apparatus of claim 1 wherein said spray shield is made of two separate assemblies joined together along an interface defined by a vertical plane which passes through the central axis thereof; and fastener means for releasably holding together said joined together assemblies.
 3. The apparatus of claim 2 wherein said hollow body member of seal assembly includes an upper annular flange spaced apart from the before mentioned flange to thereby form an annulus seal housing therebetween; said seal assembly further including spaced apart gasket members located within said housing for sealingly receiving a polished rod therethrough; said gasket members being in the form of a discontinuous toroid.
 4. The apparatus of claim 2 wherein said fastener means includes outwardly directed coacting flanges which are received in abutting relationship along said interface; and spaced apart screws placed through said flange for maintaining the flanges affixed to one another.
 5. The combination of claim 1 wherein said seal assembly includes a split annular gasket in the form of a discontinuous toroid having an inside diameter for sealingly receiving a polished rod therethrough, and having an outer diameter for being received within said hollow body member in close tolerance relationship therewith, so that said seal assembly protects the polished rod stuffing box from debris. 